A federal judge said comments a 22-year-old Vermont man made that amounted to a confession in the killing of an elderly Sheffield woman can be used in his upcoming trial on separate charges. Michael Norrie of Sheffield had asked that the statements he gave to federal law enforcement officers be suppressed because he said he did not understand his right to remain silent. The Burlington Free Press said US District Court Judge Christina Reiss ruled that there is no evidence to support Norrie’s request. It was during another January 2011 questioning that Norrie made incriminating statements about the shooting death of Mary ‘‘Pat’’ O’Hagan, 78, who disappeared on Sept. 10, 2010.